1. Field of the Invention
The present invention relates to self-contained waste treatment systems and more particularly relates to an improved self-contained wastewater treatment for use in rural areas and in the treatment of wastewater from small buildings, homes, trailer parks, office buildings and the like wherein a primary treatment vessel treats the wastewater product and the effluent passes through a filtration unit into a dosing vessel that cycles between empty and full conditions, with a pump in the dosing tank being activated when the dosing vessel reaches full position, and wherein a flow control device divides discharging flow from the pump into a first larger volume that is discharged to the environment, and a smaller flow portion that backwashes the filter, returning dirty backwash to the primary vessel.
2. General Background
It is desirable that wastewater be treated in an economical way utilizing as little energy as possible and as few moving parts as possible while removing a high percentage of solid material from the wastewater stream and while lowering the total suspended solids and bio-chemical oxygen demand of the wastewater stream. It is desirable that a minimum of sludge removal would be required since sludge disposal presents an extra problem.
It would be desirable that a wastewater treatment apparatus produce a total homogenation of the fluids received from the waste stream in order that they be properly biodegraded. Wastewater entering the unit would normally be heterogeneous in nature, containing solid waste material as well as liquid wastewater.
In aerated treatment systems, a problem is faced in that a clogging of the aeration assembly which provides oxygen and mixing to the unit will cause a degeneration of the treatment process or in fact a total stoppage of air flow to the vessel, transferring the process from aerobic to anaerobic, thus removing most treatment capability. It would be desirable that the aeration unit or air diffuser be provided that minimizes or prevents clogging by solid material which may enter the unit.
In a small wastewater treatment system for use in treatment of wastewater from single family dwellings, small businesses, apartments and the like, tertiary treatment is desirable so that underground disposal of effluent can be used such as under crops to eliminate or minimize environmentally adverse effects.
Also, particularly desirable is a system that would allow treated wastewater to be filtered, prior to environmental discharge, to remove any untreated solids. Inherent in filtration treatment is the problem of filter clogging and the possibility of excessive filter maintenance. Hence, particularly desirable is a system in which the filter may be automatically and routinely backwashed to eliminate problems of filter clogging and excessive maintenance.